Wireless communication networks exchange wireless signals with user communication devices to support user services like virtual reality, augmented reality, media conferencing, and interactive gaming. The user communication devices may be phones, computers, headsets, machines, and the like. The wireless communication network has wireless access points that exchanges wireless signals with the user communication devices.
The wireless access points and the user communication devices each have antennas to facilitate the wireless communications. In typical scenarios, the wireless access points may have several antennas, and the user communication devices have only a few antennas. Thus, the antenna configuration of a wireless access point is relatively complex, and the antenna configuration of a user communication device is relatively simple. Wireless communication technologies like massive Multiple Input Multiple Output (MIMO) and beamforming often use several antennas at the wireless access point and a few antennas at the user communication device.
Wireless Device-to-Device (D2D) communications entail the transmission and reception of wireless signals directly between user communication devices without using the wireless access point, although the wireless access point may provide D2D scheduling instructions to the user communication devices. The wireless D2D communications use the antennas in the user communication devices and not the antennas in the wireless access points.
Newer user communication devices use higher radio frequencies in the 6-60 Gigahertz range. This reduces the size of the antennas to a few millimeters in length. Numerous antennas of this size may be metallically printed on a transceiver microprocessor, and some transceiver chips may have as many as 32 or 64 antennas. Thus, newer user communication devices may have 64 or more antennas. Unfortunately, the newer user communication devices are often still battery powered, and the large number of antennas causes a larger battery drain.
When a battery-powered user communication device has substantially drained its battery, the device often enters a low-power mode to conserve remaining battery power. The low-power mode may entail a reduction in the number of antennas being used. For example, a user communication device using all 64 of its antennas may reduce that number to eight in a low-power mode. The large number of antennas in some user communication devices adds complexity to low-power mode given the higher number of antenna configuration options. The antenna complexity in low-power mode is even more challenging when the user communication devices are engaging in wireless D2D communications.